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Species Range
Tibetan macaques live in China and the
extreme North of India, spreading from Huangshan (Yellow mountain) in
Anhui Province, to Tibet, but their exact distribution is not known. The
species is listed as conservation dependent. In some areas their territories
overlap with rhesus macaques, but rhesus tend to stay at lower altitudes
(warmer climate) than the Tibetan macaques. Consequently, Tibetan macaques
grow a thicker fur coat to cope with the cold environment of higher altitudes.
The number of groups around Huangshan has been estimated to 14, accounting
for more than 400 monkeys. Surveys are curently being done by Chinese
researchers for a better estimate of the actual ranges and numbers of
Tibetan macaques in China. |
Life span
In many respects Tibetan macaques are no different than
all other species of macaques. They
live in groups of tens of individuals, composed of adult males and females,
plus their youngsters. On average, the life span of a healthy individual
can reach 25-30 years, females living slightly longer than males. Usually
females remain in the group where they were born, and many males leave
the group upon reaching adulthood (about 8 years old). Males may change
groups more than once within their life time. In general (but not as a
rule) females of this species have red skin around their eyes(see picture
on right). Tibetan macaques are the largest macaques in the world.
Females have smaller bodies and canines than males. Females
start to give birth when they are about 5 years old, which is their time
of adulthood, and continue to do so until they die. The pregnancy lasts
for 6 months, and most infants are born in the first months of the year
(January-February). Exceptions are common however. Different from adults
which have dark fur, the infants are whitish. The coat color darkens with
maturation, but the final color varies from light brown to black. The
infants suckle for about a year, and may continue to do so for a while
if their mother does not give birth the next year. However, even during
the first 6 months of life the infants increasingly supplement their diet
with natural (and human provided) food. Nevertheless, an infant is highly
dependent on mother's help for the first few years of life. The most critical
period in the life of an individual is the first year of life. |
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Causes of death
In general, an individual reaching 4 years of age has relatively
high chances of reaching far into adulthood (barring accidents). Males
face serious challenges at the time of immigration to other groups. At
least for the groups around Huangshan, there are no natural predators.
Eagles, wild pigs, venomous snakes, and snow leopards are present in the
area, but there are no credible accounts of witnessed attacks on monkeys.
However, monkeys were observed to give alarm calls and run into trees
when big birds, snakes and wild pigs were around. Males are very strong
(see second left picture) and they defend the females and youngsters against
outsiders, including people and dogs. By far the most serious threat comes
from humans: habitat destruction, herbicide and pesticide poisoning, human
transmitted diseases and poaching (Tibetan macaques are protected by Chinese
law). Fights between adults, especially males, are a common source of
injuries. Deaths have been reported in adult males following fights. Infants
and juveniles also tend to fall victims to adults when targeted by frustrated
individuals. |
Diet
Tibetan macaques are highly reliant on leaves, fruits,
grass and to a lesser extent on flowers, roots, and insects. When available,
bamboo shoots and bamboo leaves are welcome. Like
other monkeys they will happily feed on plants grown by or
food provided by humans, but do not raid crops as rhesus macaques do.
Buddhist Monks at Jiuhua Shan, our staff at Huangshan and tourists at
Emei Shan, provide a few groups of Tibetan macaques with staple food.
However, if not done under certain conditions, provisioning can cause
serious problems for monkeys and people. Side effects of human provisioning
are discussed in the Essential rules section.
The above picture shows an adult female in the river gathering provisioned
corn. |
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Behavior
Contrary to many assumptions and documentary
movies, macaques spend much of their time resting. Tibetan macaques are
no exception. Except for the unusual commotion associated with feeding
or traveling, a lot of time is spent sitting, sleeping or grooming each
other. This is not to say they doze all day or are slow fellows. During
one day they repeatedly travel through their home range (about 3 Km in
diameter for our group) to forage, find shelter against rain, or shade
when sunny. If necessary, they can climb steep rocky slopes in no time,
and are capable of acrobatic jumps from tree to tree. Within the group
they have preferences for some partners and avoid others. In general,
friends and relatives tend to cluster together. Macaque societies are
hierarchical groups, that is, individuals within a group do rank relative
to each other. Higher ranking individuals get better access to resources.
Males follow females in the hope of mating with them. The higher the rank
of a male, the easier for him to secure matings (unchallenged by other
males), thus the more offspring he may sire in the next generation. Females,
however, can and do avoid mating especially when approached by males known
for their aggressiveness. From studies done on Tibetan macaques at Emei
Shan and Huang Shan, the average tenure time for the alpha male (the highest
ranking male) is about one year. He is usually a young (8-9 years old)
and strong adult male. With age, the male's rank decreases. Females also
tend to change ranks. In many respects a high ranking female can dominate
lower ranking males, despite being smaller. This is due to help from other
individuals, especially high ranking males. Macaques are a "political"
society, with a complex network of relationships. By carefully cultivating
relationships and relying on them when necessary, an individual is able
to influence the interactions with others, and make his/her life in the
group manageable if not smooth. This is very necessary in macaques, who
are bad tempered compared with other non-human primates (prosimians, monkeys
and apes). When groups reach large sizes (in the 40-50 range) some individuals
(males, females and juveniles) split from the main group and form a different
one, moving to a different home range. Group fissioning is a natural process
generated by higher competition over resources, food and access to mating
(for males) in the home range. Usually, but not as a rule, the lowest
ranking individuals will split from the main group. Since the beginning
of the studies on the Yulingkeng group (the one observed by tourists at
Huangshan Monkey Valley), 3 fissions have occurred resulting in 3 new
groups that live in adjacent territories. |
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Additional readings
Detailed information about Tibetan macaques can be
found in scientific publications (in Chinese and English). Here we
list 3 sources of more general interest:
Li, Jin Hua (1999). The Tibetan macaque
society. A field study. Hefei, China: Anhui University Press [in Chinese]
Ogawa, Hideshi (1995). Bridging behavior
and other affiliative interactions among male Tibetan macaques (Macaca
thibetana). International Journal of Primatology, 16, 707-729.
Zhao, Qi-Kun (1996). Etho-ecology of
Tibetan macaques at Mount Emei, China. In: Fa, J., Lindburg, D.G. (eds.).
Evolution and ecology of macaque societies. p. 263-289. Cambridge: Cambridge
Univ Press [This book is a very good synthesis about macaques] |